Device for producing electric pulsations.



DEVICE FOR PRODUCING ELECTRIC'PULSATIONS.

APPLICATION FILED SEPT. 23. 1912.

1,134,137, Patented Apr. 6, 1915.

wj BY 07am 17W A TTO RNZ JOHN F. KELLY, 0F PITTSFIELD", MASSACHUSETTS.

DEVICE FOR PRODUCING ELECTRIC PUL$ATIONS.

Specification of Letters Patent.

Application filed September 28, 1912. Serial No. 722,984.

To all whom it may concern:

Be it known that I, JOHN F. KELLY,acitizen of the United States ofAmerica, residing at Pittsfield, in the county of Berkshire and State ofMassachusetts, have invented new and useful Improvements in Devices forProducing Electric Pulsations, of which the following is aspecification.

This invention relates to improvements in devices for producing electricpulsations in which a rotating make and break wheel is employed, thecontact sectors of which are placed on a portion only of its surface;and the objects of my improvements are; first, to reduce the cost ofconstruction of such wheels, second, to arrange a suitable number ofbrushes to cooperate with the com paratively short train of contactsectors so as to furnish the desired number of pulsa: tions perrevolution.

This invention is designed for opening and closing an electric circuitfor the purpose of producing and transmitting electrical impulses toelectro-magnets which are used to operate or set a string or plate invibration. It is well-known that the natural rate of vibration of amusical string or wire is not, in every instance, a whole number oftimes per second. It is, therefore,

necessary in providing electro-magnetic means for vibrating the wire toenergize the magnet as many times per second as the wire vibrates, but,as stated, since the wire does not vibrate a whole number of times persecond, the energization of the magnet must correspond as nearly aspossible thereto. The present invention has, therefore, as one of itsobjects to open and close the circuit to the operating magnets as manytimes as the wire or string vibrates. In accordance with this principlerelating to the vibration of a wire, it, therefore, becomes necessary toarrange the contacts and insulation spaces on the rotating wheeldistances apart and according to number so as to open and-close thecircuit as nearly as possible the same number of times as the wire orplate vibrates, regard being had to the fractional parts of a vibrationin a given interval of time; usually a second is the period employed inmeasuring the rate of vibration of a wire or plate.

Referring to the drawings formingapart of the specification,Figure 1 isa diagrammatic View of the improvement showing a make and break wheelembodying the invention. It is shown associated with means to vibrate asonorous member if desired. Fig. 2 is a sectional View of the wheel,taken on a plane passing through the axis of the shaft.

Referring to the drawings in detail a designates the wheel as a wholewhich is suitably secured to a shaft 6.

c designates contact sectors that are located on the peripheryandelectrically connected with each other by the web-portion of thewheel. The contacts 0, as shown, are in electric contact with the metalbody portion of the wheel which is secured to the shaft 6. Thesecontacts are located on only a comparatively small portion of thecircumference as shown, the distance between two of the contacts may bean aliquot part of 860. 0' designates the ring of insulation in whichthe contacts 0 are embedded.

d designates brushes suitably arranged at equal angles with relation toeach other so as to transmit the electric impulses to the operatingmagnets in substantially a regular manner depending, of course, upon thespaced relation of the contacts.

In order to illustrate an application of the present invention it isshown associated with a sonorous body 6, which may represent a wire orplate,- a source of current is designated at from one terminal of whicha wire 9 leads to an electro-magnet h, from its opposite terminal a wire11 is connected to the brushes d by means of a wire j. From the otherterminal of the magnet h a wire 70 connects to a brush m that engagesthe shaft 6. From this construction it is clear that when the make andbreak wheel is'rotated that electrical impulses or pulsations will beproduced and transmitted to the electromagnet h in substantially aregular manner. By placing contacts on a portion only of the wheel andincreasing the number of brushes the same number of impulses orpulsations will be produced and transmitted as placing the contacts allaround its surface and using only a single brush. As shown there arethree brushes employed and contacts placed on practically one-third ofthe circumfer- Patented Apr.6, 1915. a

ence. Where a high rate of impulses is de-' sired it is clear that it ischeaper to increase the number of brushes and lessen the number ofcontacts than to increase the number of contacts and use only a singlebrush as heretofore. When the wheel is employed to cause the vibrationof a string or plate the contact sectors are made short to produce aquick pull or plucking action on the wire when the electro-magnet h isenergized, similar to plucking a violin string by hand. It is, ofcourse, not necessary that the angular distance between any two of thecontacts is an aliquot part of 860 as the invention is not limited toany such construction. It is necessary, however, that the angulardistance between any two contacts shall be the same.

It is to be understood that the space covered by the group of contactsmay not be an aliquot part of the circle as, for example,

the space occupied by the group of contacts might occupy 3/16, 3/17, orl/l'l' of the circumference in which case the impulses would not be analiquot number because the angle of distance between the brushes is notequal. It is, of course, obvious that the space not occupied by theregular train of contacts-and insulating spaces is at least as wide asthe pitch.

What I claim, is

1. In a rotary make and break device to open and close an electricalcircuit to produce and transmit a succession of electrical impulses, aplurality of conducting contacts arranged in a single group on a portiononly of the peripheral surface. of the make and break device, a sourceof electrical energy, a plurality of brushes connected in parallel toone terminal of the source of electrical energy, and connections fromthe other terminal of the source of electrical energy to the otherterminals of the brushes to engage the contacts and spaced from eachother to produce a succession of impulses, the remainder of theperipheral surface being composed of insulating material, as described.

2. A rotary electric circuit controlling device, comprising incombination, a plurality of conducting contacts distributed in a singlegroup 011 the periphery thereof, means to electrically connect oneterminal of each of the contacts with each other, a plurality of brushesequally spaced from each other to engage the contacts in succession,said brushes being electrically connected together and spaced from eachother to cooperate with the other terminal of each of the contacts toproduce electrical impulses of equal duration of interval per revolutionof the controlling device, and means to insulate the other terminal ofeach of the contacts from each other, I

v 3. In a device of the character described comprising a single'rotormember, contact elements on said member and distributed over one areonly of its peripheral surface;

the remainder of the are being composed of insulating material, brushesequally spaced terminal thereof in parallel arrangement.

and engaging the contacts and connections from the other terminal of thesource of electrical energy and to the contacts as described.

5. In a circular rotary make and break device for opening and closing anelectrical circuit at substantially regular intervals, 9.

rotating member having a periphery of in sulating material, a pluralityof conducting contacts spaced equidistantly from each other and arrangedin a group covering part only of the peripheral surface of the rotatingmember, a source of electrical energy, a plurality of brushes spacedequidistantly apart around the periphery of the rotary member andconnected in parallel to one terminal of the source of energy,connections from the other terminal of said source to the contactswhereby the current will be interrupted in succession through each ofsaid brushes upon rotation of said rotary member.

6. In a circular rotary make and break device for opening and closing anelectric circuit at substantially regular intervals, a rotating memberhaving its periphery formed of insulating material, a plurality ofconducting contacts spaced equidistant from each other and arranged in agroup which covers a part only of the peripheral surface of the rotarymember, the portion of the peripheral surface not covered by the groupof contacts being at least as wide as the pitch, a source of electricalenergy, a plurality of conducting brushes for engaging the perlpheralsurface of the rotary member and spaced equidistantly apart around thesaid surface of the rotary member and connected in parallel to oneterminal of the source of energy, connections from the other terminal ofsaid source to the contacts whereby the current will be interrupted insuccession through each of said brushes upon rotation of said rotarymembers.

7. A device for producing electrical pulsasegments in order to produce aplucking or tions, comprising a rotor member, the pepicking action.riphery of which is divided into insulating and conducting segments, thesegments be- JOHN 5 ing distributed over an arc of the periphery,Witnesses:

and the length of the conducting segments HARRY W. BOWEN,

being narrower than the adjacent insulating K. I. CLEMONS.

